Certain two-wheeled bicycles have grown in popularity in recent years. Among these bicycles or "bikes" are rugged off-road bicycles commonly referred to as "dirt bikes" or "motocross bikes" (or, "BMX bikes"). Collectively, these BMX-type bikes are subject to thrilling maneuvering by their riders, including jumps and limited aerobatics. Often while operating or riding such a bike, a rider desires to lift the bike's front wheel off of a ground plane upon which the bike is traveling on its two wheels, in performance of a maneuver known as a "wheelie". Performing a wheelie (or "popping a wheelie") with a BMX-type bike (or, for that matter, any bicycle) usually involves the rider rotating the bike's frame upward and backward about the bike's rear wheel axle, while balancing on the bike's rear wheel as the bike maintains linear motion along the ground. In this manner, the front wheel leaves the ground to maintain a somewhat constant vertical displacement thereabove, and the bike essentially performs like a unicycle during the wheelie maneuver until the rider returns the front wheel to the ground at the end of the wheelie maneuver. "Wheelies" really have no inherent practical value in safe and efficient operation of a bicycle; however, aggressive riders typically desire to perform them in a display of coordination and bicycle mastery to their peers. Further, riders also enjoy performing certain stunts while popping wheelies such as spinning or twisting the vertically displaced front wheel (again, in a display of coordination and balance).
As may be appreciated by anyone familiar with bicycles, popping a wheelie introduces stability problems. That is, in a wheelie, bicycle stability is generally reduced since the bicycle front wheel is lifted off of ground contact. Balance and "seat of the pants" center of gravity manipulation by the rider become of great importance to maintain the wheelie. Further, in popping a wheelie there exists a modicum of danger to the rider. In particular, a rider's physical safety is compromised when the bike frame is rotated too far upward and backward about the bike's rear wheel axle. In such an over-rotated position, the rider's mass will tend to continue backward past the bike's center of gravity established during the wheelie maneuver and be unrecoverable from this center of gravity departure, resulting then in a painful collision with the ground.
Numerous attempts have been made to stabilize a bike while popping a wheelie and to provide a margin of safety such that the rider does not over-rotate the bike as aforedescribed. Nearly all of these attempts utilize a structure extending rearwardly from the bike having at least one ground contact member that prevents the bike from over-rotating during a wheelie.
For example, U.S. Pat. No. 3,653,679 issued to Howard, entitled Bicycle Attachment and Combination, discloses a bicycle attachment including a frame that is attached at one end to a rear portion of a bicycle. A wheel or pair of wheels is attached to the frame's outboard end. The attachment acts to limit angular movement between the bicycle and the attachment when the bicycle's front wheel is raised.
In U.S. Pat. No. 3,888,511 issued to Parrilla, entitled Safety Device to Prevent Tipping a Bicycle, a bicycle is prevented from backwardly tipping over when the bicycle's front wheel is raised by use of a frame having two linear rigid horizontal frame members.
In U.S. Pat. No. 3,961,810 issued to Arico, entitled Bicycle Safety and Conversion Wheel, the disclosed device incorporates a structure having a pair of frame members extending outwardly from a rear portion of a bicycle. The structure includes what essentially resembles a rear portion of a typical skateboard. Upon popping a wheelie the structure contacts the ground for stability. Further, a bicyclist performing the wheelie may ride on the skateboard-like portion of the structure itself during the wheelie.
U.S. Pat. No. 4,153,268 issued to Wilson et al. and entitled Cycle Stabilizing Accessory discloses a pair of adjustable length members that serve as an attachment frame to carry a pair of outboard stabilizing wheels.
In U.S. Pat. No. 4,154,452 issued to Newman, entitled Bicycle Safety Accessory, a spaced pair of generally parallel support arms extends rearwardly from each side of a bicycle rear wheel. A ground contact member or accessory wheel is secured to a rearward end of the paired support arms.
U.S. Pat. No. 4,353,571 issued to Anderson and entitled Wheelie Support discloses a device that enables a rider to perform a wheelie by resting on an outboard wheelie support attached to a bicycle's rear wheel fender.
In U.S. Pat. No. 4,367,883 issued to Anderson, entitled Wheelie Support, a device is disclosed that provides contact, during a wheelie, on the rear bicycle wheel and on a wheelie support. The wheelie support extends forward of the rear wheel, and is displaced above ground level. Ground contact of the wheelie support is made when popping a wheelie.
U.S. Pat. No. 5,242,183 issued to Oberg et al. and entitled Bicycle Accessory for Stabilization while Popping Wheelies provides an accessory including a pair of frame members, and also a substantially U-shaped fifth frame member, attached to a bicycle.
In U.S. Pat. No. 5,330,221 issued to Sutton and entitled Bicycle Wheelie Balancing Device a device is attached to a bicycle to aid a rider in learning to "pop a wheelie." The device includes a support frame attached to the bicycle, with an opposite end of the frame attached to a tandem wheel assembly resembling a portion of a skateboard similar to that illustrated in the aforedescribed U.S. Pat. No. Arico '810.
These above patents, however, do not adequately address, for instance, related problems introduced by the various stabilizing devices themselves. Specifically, in operation, such devices tend to skid along the ground because of their rigid bicycle attachment, thereby degrading and shortening the useful lives of their ground contact members. Also, in operation when the devices contact the ground, lateral forces are often imparted to the bicycle frames such that the bicycles become unstable in a left-to-right-to-left sense during a wheelie. Additionally, such devices may actually prevent performance of a wheelie because of ground contact occurring too soon after initiation of the wheelie maneuver.
Therefore, there exists a need for a wheelie stabilizer and safety device that aids the rider in performance of the wheelie by stabilizing the maneuver, and that also provides protection against over-rotation during the maneuver. A need exists for these functions to be provided without skidding a ground contact stabilizer member, nor imparting unwanted lateral forces to the bicycle frame, and without hindering desired wheelie performance.